Posted
by
Unknown Lamer
on Tuesday January 31, 2012 @03:11AM
from the sr-819-around-the-corner dept.

cylonlover writes with an excerpt from a Gizmag article: "The cell membrane is one of the most important components of a cell because it separates the interior from the environment and controls the movement of substances in and out of the cell. In a move that brings mankind another step closer to being able to create artificial life forms from scratch, chemists from the University of California, San Diego (UCSD), and Harvard University have created artificial self-assembling cell membranes using a novel chemical reaction. The chemists hope their creation will help shed light on the origins of life."
The full paper is available in the Journal of the American Chemical Society (behind a paywall).

Neat. I used to work for the UCSD Bioengineering department. Many, many smart people worked there. Much more so than the San Diego Supercomputer Center during the tech boom (half the people they hired during that time period were people who'd read a "Learn Programming in 30 Days" book, or whatever, because anyone with any skills were going into industry).

We're still some ways off! So far we've got the ability to throw a new membrane and a chromosome at a pre-existing cell; there's still a ton of stuff that goes on in between. We still don't know exactly how a lot of it works; there are lots of little protein structures in bacterial cytoplasm that will take a lot of diligent study to figure out. Some day, though. Some day.

(Also, is it just me, or is S nowhere near Y on any keyboard layout ever?)

I understand scientists do this to better understand the world we live in but why do you want to create life from scratch? We now have tools to manipulate existing cells to our whim. A cell wall is a very complex thing. The word "wall" is misleading. It is semi permeable and there are channels and pores that actively (uses ATP) pump nutrients in an out. There are enzymes, receptors, emitters and many other biomolecules that make up a cell wall. And this is only the cell wall. We haven't even talked about th

I don't think that life from scratch and FTL are completely interchangeable as analogies for each other. FTL is very subtle and almost reasonable when one goes to prove it theoretically, but to what I know it has been shown to be a fallacy. Life from scratch on the other hand, is still possible in theory: basically some elements that come together to form more complicated compounds. There's a lot more to be known on the practical side: how exactly do these compounds form (aminoacids as part of starforming c

Well, the scientific reason is as FunkyLich was sorta reaching for: if we can put together a cell from scratch, then we will be certain that we've accounted (and hopefully understood) all of the parts involved. The major reason, however, is commercially driven: if you can generate simple microbes abiotically, that opens the doors for a huge range of synthetic biology devices. And the associated profits.

Actually the challenge of deciding what is and isn't life is an ongoing mess; we haven't quite come to a universal agreement about some of the attributes. It's more of a definition issue than a chemistry one at this point, in fact! We've done a lot of experiments and discovered quite a few ways to kill a cell.:)

The suggestion, at least from the blurb, is that this may have been important to the origins of life. And how does it not have much to do with realistic cell membranes? You have a phospholipid bilayer with these things. That's the same thing as cell membranes basically, throw in some proteins (researchers have been adding proteins to artificial bilayers for decades) and you can get them to do exactly the same things that cell membranes do.

I read the actual article and the authors have used a chemical reaction (that is not the same as the one used in nature), to make lipids (but not the actual ones that nature makes). Once they got the lipids the bilayer forms itself, but that is nothing new.
The reaction is carried out in water, and the substrates are not reactive unless a catalyst is added, which leads them to claim that this is more "natural" than a standard chemical reaction. Using the word "life" or "nature" in this context is IMHO not

Well, they say it is biomimetic. It's about as close as anybody ever gets. The important part is that the properties of the artificial membranes (at least the ones they measured) are the same as for the natural membranes they were trying to mimic. It's a JACS communication, so there isn't a lot of detail, but it looks like a pretty good model. There are a lot of potential uses, not the least of which is they can more easily study how additional components in the membrane (ex: proteins) affect its properties

No. In fact, they mention in the paper that is fairly difficult to do. Knowing something about the enzyme megacomplexes that catalyze these reactions, I believe them. Hence why they developed this system, and why it made it into JACS (click chemistry by itself is nothing new). Overall, the triazole would not be expected to drastically affect the properties of the membrane, which they affirm by measuring a handful of bulk properties. So I think it's a pretty good model.

Althought the paper manages not to mention it, the chemistry they are doing here is (the alkyne azide cyclisation) is part of "click" chemistry [wikipedia.org], which is quite well known.

What the paper doesn't really say is whether they hope to accomplish anything further with this. As with all biomimetic reaction, it seems (to me) that synthesising a single step in the process may be intersting, without doing all the previous steps, is there any practical point?

The minimal nature of our approach will likely lend itself to further elaboration, as we envision incorporating this system into a fully synthetic cell. We are also exploring practical applications of triazole membrane assembly, for instance in packaging and delivering therapeutics, improving transfection efficiencies, reconstituting functional membrane proteins, and performing confined biochemical reactions.